Evolution of human brain functions: the functional structure of human consciousness

2009 ◽  
Vol 43 (11) ◽  
pp. 994-1006 ◽  
Author(s):  
C. Robert Cloninger
Mind Shift ◽  
2021 ◽  
pp. 411-436
Author(s):  
John Parrington

This chapter returns to the various alternative views about human consciousness first mentioned at the start of this book, and assesses how this book’s account compares to, and hopefully builds on, these other viewpoints. The view of human consciousness developed in this book can explain the uniqueness of our species’ conscious awareness, but in an entirely materialistic fashion. This approach views language—the system of abstract symbols linked in a grammatical structure but also one that connects the individual to the world outside via word meaning—and other forms of human culture like music, art, and literature, as a material force that has reshaped human brain functions at every level. This has led to a qualitative shift in such functions, compared to that of every other species, including our closest animal cousins, the great apes. Unlike a purely ‘bottom up’ approach to human brain function, this view sees language, as well as other mediators of human culture, as imposing both structural and dynamic changes in our brains. Structurally, it sees the different brain regions, as well as their interconnections, as altered in humans. The chapter then reflects on what impact, if any, might this approach to understanding human consciousness have on diagnosis and treatment of mental disorders.


KronoScope ◽  
2013 ◽  
Vol 13 (2) ◽  
pp. 228-239
Author(s):  
Rémy Lestienne

Abstract J.T. Fraser used to emphasize the uniqueness of the human brain in its capacity for apprehending the various dimensions of “nootemporality” (Fraser 1982 and 1987). Indeed, our brain allows us to sense the flow of time, to measure delays, to remember past events or to predict future outcomes. In these achievements, the human brain reveals itself far superior to its animal counterpart. Women and men are the only beings, I believe, who are able to think about what they will do the next day. This is because such a thought implies three intellectual abilities that are proper to mankind: the capacity to take their own thoughts as objects of their thinking, the ability of mental time travels—to the past thanks to their episodic memory or to the future—and the possibility to project very far into the future, as a consequence of their enlarged and complexified forebrain. But there are severe limits to our timing abilities of which we are often unaware. Our sensibility to the passing time, like other of our intellectual abilities, is often competing with other brain functions, because they use at least in part the same neural networks. This is particularly the case regarding attention. The deeper the level of attention required, the looser is our perception of the flow of time. When we pay attention to something, when we fix our attention, then our inner sense of the flux of time freezes. This limitation should not sound too unfamiliar to the reader of J.T. Fraser who wrote in his book Time, Conflict, and Human Values (1999) about “time as a nested hierarchy of unresolvable conflicts.”


Brain ◽  
2019 ◽  
Vol 142 (12) ◽  
pp. 3991-4002 ◽  
Author(s):  
Martijn P van den Heuvel ◽  
Lianne H Scholtens ◽  
Siemon C de Lange ◽  
Rory Pijnenburg ◽  
Wiepke Cahn ◽  
...  

See Vértes and Seidlitz (doi:10.1093/brain/awz353) for a scientific commentary on this article. Is schizophrenia a by-product of human brain evolution? By comparing the human and chimpanzee connectomes, van den Heuvel et al. demonstrate that connections unique to the human brain show greater involvement in schizophrenia pathology. Modifications in service of higher-order brain functions may have rendered the brain more vulnerable to dysfunction.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mohammad Ali Salehinejad ◽  
Miles Wischnewski ◽  
Elham Ghanavati ◽  
Mohsen Mosayebi-Samani ◽  
Min-Fang Kuo ◽  
...  

AbstractCircadian rhythms have natural relative variations among humans known as chronotype. Chronotype or being a morning or evening person, has a specific physiological, behavioural, and also genetic manifestation. Whether and how chronotype modulates human brain physiology and cognition is, however, not well understood. Here we examine how cortical excitability, neuroplasticity, and cognition are associated with chronotype in early and late chronotype individuals. We monitor motor cortical excitability, brain stimulation-induced neuroplasticity, and examine motor learning and cognitive functions at circadian-preferred and non-preferred times of day in 32 individuals. Motor learning and cognitive performance (working memory, and attention) along with their electrophysiological components are significantly enhanced at the circadian-preferred, compared to the non-preferred time. This outperformance is associated with enhanced cortical excitability (prominent cortical facilitation, diminished cortical inhibition), and long-term potentiation/depression-like plasticity. Our data show convergent findings of how chronotype can modulate human brain functions from basic physiological mechanisms to behaviour and higher-order cognition.


2017 ◽  
pp. 115-186 ◽  
Author(s):  
John C. Ashton ◽  
Megan J. Dowie ◽  
Michelle Glass

Mind Shift ◽  
2021 ◽  
pp. 19-31
Author(s):  
John Parrington

This chapter discusses different views on the basis of human consciousness. A major problem with much popular speculation about the biological roots of consciousness is that those who advocate a gene-based view of consciousness often appear to have little understanding of modern genetics, while speculation about how brain structures shape that consciousness often bear little resemblance to emerging knowledge about the complexity of an actual human brain. There is a common thread here, which is that idealised genes and brains have been substituted for real ones. Unfortunately, because of this tendency, it is not clear how much we have really advanced forwards from René Descartes and his belief that the human mind was an unknowable entity, or for that matter, the behaviourists with their view that the human mind could be treated as a black box. In contrast, to understand human consciousness, there is a need to understand real genes, real brains, and how these have evolved in humans compared to other species.


Author(s):  
Susan Blackmore

‘The human brain’ considers the brain as a vast network of connections from which come our extraordinary abilities: perception, learning, memory, reasoning, language, and somehow or another—consciousness. Different areas deal with vision, hearing, speech, body image, motor control, and forward planning. They are all linked, but this is not done through one central processor, but by millions of criss-crossing connections. By contrast, human consciousness seems to be unified. A successful science of consciousness must therefore explain the contents of consciousness, the continuity of consciousness, and the self who is conscious. Research linking consciousness to brain function is discussed along with conditions such as synaesthesia, blindsight, stroke damage, and amnesia.


Mind Shift ◽  
2021 ◽  
pp. 80-91
Author(s):  
John Parrington

This chapter focuses on the role that genes play in the formation of human consciousness. While the genome has generally been defined as the sum of the genes in an organism, the more we study real genomes, the more we realise that viewing them in this way is a major oversimplification of their true complexity. Perhaps the most surprising outcome of the Human Genome Project was the realization that genes only represent a small fraction of the total DNA sequence. More recently, evidence has been accumulating to show that a significant proportion of the ‘non-coding’ DNA plays key roles in gene regulation—that is, determining which genes get switched on or off and when. In addition, instead of DNA being seen as the sole controller of cellular function, there is now growing recognition that RNA also plays a key role. Meanwhile, the new science of ‘epigenetics’ is revealing that the DNA ‘recipe’ for each organism appears far more responsive to the environment than previously thought, both to changes in the cellular environment, and those outside the organism itself. These new ways of looking at the genome have important implications for the understanding of how the human brain works, and of some of the factors that might make it unique compared to those of other species.


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